Use FSEvents for recursive file watch on Mac

base/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/android/rules.gni")
 import("//build/config/ui.gni")
 
 component("base") {
   sources = [
     "third_party/dmg_fp/dmg_fp.h",
@@ skipping 166 matching lines @@
     "files/file_win.cc",
     "files/file_enumerator.cc",
     "files/file_enumerator.h",
     "files/file_enumerator_posix.cc",
     "files/file_enumerator_win.cc",
     "files/file_path.cc",
     "files/file_path.h",
     "files/file_path_constants.cc",
     "files/file_path_watcher.cc",
     "files/file_path_watcher.h",
+    "files/file_path_watcher_fsevents.cc",
+    "files/file_path_watcher_fsevents.h",
     "files/file_path_watcher_kqueue.cc",
+    "files/file_path_watcher_kqueue.h",
     "files/file_path_watcher_linux.cc",
+    "files/file_path_watcher_mac.cc",
     "files/file_path_watcher_win.cc",
     "files/file_proxy.cc",
     "files/file_proxy.h",
     "files/file_util_proxy.cc",
     "files/file_util_proxy.h",
     "files/important_file_writer.cc",
     "files/important_file_writer.h",
     "files/memory_mapped_file.cc",
     "files/memory_mapped_file.h",
     "files/memory_mapped_file_posix.cc",
@@ skipping 630 matching lines @@
   # Mac.
   if (is_mac) {
     sources -= [
       "base_paths_posix.cc",
       "native_library_posix.cc",
       "strings/sys_string_conversions_posix.cc",
     ]
     deps += [ "//third_party/mach_override" ]
   } else {
     # Non-Mac.
-    sources -= [ "files/file_path_watcher_kqueue.cc" ]
+    sources -= [
+      "files/file_path_watcher_fsevents.cc",
+      "files/file_path_watcher_fsevents.h",
+      "files/file_path_watcher_kqueue.cc",
+      "files/file_path_watcher_kqueue.h",
+    ]
   }
 
   # Linux.
   if (is_linux) {
     # TODO(brettw) this will need to be parameterized at some point.
     linux_configs = [
       "//build/config/linux:glib",
     ]
 
     configs += linux_configs
@@ skipping 502 matching lines @@
     source_prereqs = [
       "android/java/templates/native_libraries_array.h",
       ]
 
     package_name = "org/chromium/base/library_loader"
     include_path = "android/java/templates"
   }
 
 
 }